H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
H02K—DYNAMO-ELECTRIC MACHINES
H02K37/00—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors
H02K37/10—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type
H02K37/12—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type with stationary armatures and rotating magnets